RWRandGenR250 Class Reference

Generates random numbers uniformly distributed over the interval [0, 1]. More...

#include <rw/randr250.h>

Public Member Functions
	RWRandGenR250 ()
	RWRandGenR250 (unsigned long seed)
	RWRandGenR250 (const RWRandGenR250 &u)
bool	operator!= (const RWRandGenR250 &u) const
double	operator() ()
RWRandGenR250 &	operator= (const RWRandGenR250 &u)
bool	operator== (const RWRandGenR250 &u) const
void	printOn (std::ostream &s) const
void	restart ()
void	restart (unsigned long seed)
void	restoreFrom (RWFile &)
void	restoreFrom (RWvistream &)
void	saveOn (RWFile &) const
void	saveOn (RWvostream &) const
void	scanFrom (std::istream &s)
unsigned long	seed () const

Related Functions
(Note that these are not member functions.)
std::ostream &	operator<< (std::ostream &s, const RWRandGenR250 &gen)
std::istream &	operator>> (std::istream &s, RWRandGenR250 &gen)

Detailed Description

Class RWRandGenR250 generates random numbers uniformly distributed over the interval [0, 1], and may be used instead of class RWRandGenerator as a template parameter to any of the distribution generators derived from abstract base class RWTRand. RWRandGenR250 is a generalized feedback shift register generator.

Unlike class RWRandGenerator, each instance of RWRandGenR250 contains and maintains its own, independent state. This can make it easier to use in some situations. The "internal state" of an instance of RWRandGenR250 consists of a seed, an array of unsigned longs known as the "state vector" and an integer index into that state vector. (S. Kirkpatrick and E. Stoll, Journal of Computational Physics, 40, p. 517 (1981).

Synopsis

#include <rw/randr250.h>
RWRandGenR250 gen;

Constructor & Destructor Documentation

RWRandGenR250::RWRandGenR250

(

)

Constructs a generator, arbitrarily seeded by a call to the time() function.

RWRandGenR250::RWRandGenR250

(

unsigned long

seed

)

Constructs a generator with a specified seed.

RWRandGenR250::RWRandGenR250

(

const RWRandGenR250 &

u

)

Constructs a copy of u. The copy's state will equal the state of u at the time the copy is created, but will not share the state of u.

Member Function Documentation

bool RWRandGenR250::operator!=

(

const RWRandGenR250 &

u

)

const

Returns true for two distinct instances of RWRandGenR250 if their internal states differ. "(x != x)" returns false.

double RWRandGenR250::operator()

(

)

Returns a random double in [0,1].

RWRandGenR250& RWRandGenR250::operator=

(

const RWRandGenR250 &

u

)

Sets an instance of RWRandGenR250 equal to the state of instance u.

bool RWRandGenR250::operator==

(

const RWRandGenR250 &

u

)

const

Returns true for two distinct instances of RWRandGenR250 if they will return identical sequences of values.

void RWRandGenR250::printOn

(

std::ostream &

s

)

const

Outputs a summary of self's internal state on ostream s.

void RWRandGenR250::restart

(

)

Restarts the generator, arbitrarily seeding it by a call to the time() function.

void RWRandGenR250::restart

(

unsigned long

seed

)

Restarts the generator with specified seed.

void RWRandGenR250::restoreFrom

(

RWFile &

)

Restores internal state of self from an RWFile.

void RWRandGenR250::restoreFrom

(

RWvistream &

)

Restores internal state of self from a virtual stream.

void RWRandGenR250::saveOn

(

RWFile &

)

const

Stores internal state of self in a binary format to an RWFile.

void RWRandGenR250::saveOn

(

RWvostream &

)

const

Stores internal state of self to a virtual stream.

void RWRandGenR250::scanFrom

(

std::istream &

s

)

Inputs an internal state from istream s to self.

unsigned long RWRandGenR250::seed

(

)

const

Returns the seed used to initialize the generator.

Friends And Related Function Documentation

std::ostream & operator<< ( std::ostream &  s, const RWRandGenR250 &  gen  )

related

Outputs a summary of gen's internal state on ostream s.

std::istream & operator>> ( std::istream &  s, RWRandGenR250 &  gen  )

related

Inputs an internal state from istream s to gen.